The present invention is directed to well tools for oil and gas wells for mounting gas lift valves internally of coiled tubing.
The use of gas lift valves connected to the outside of coiled tubing for providing gas lift to the interior of production well tubing is disclosed in U.S. Pat. No. 4,844,166. However, such externally connected gas lift mandrels have the disadvantage that they cannot be conveniently lowered through various well head equipment, nor can they be satisfactorily reeled onto the reel as the coiled tubing is installed into and removed from the production tubing string, and they extend into and restrict the annulus between the coiled tubing and the production tubing.
The present invention is directed to a gas lift assembly in which the gas lift valves are mounted internally of the coiled tubing and have the advantages that they may connected in the coiled tubing and stored on a coiled tubing reel, and may be injected through well head equipment which distorts the coiled tubing into an oval shape for passage through the injector head.